Register Descriptions; Timer Counter (Tcnt); Timer Control/Status Register (Tcsr) - Renesas H8S/2633 Series Hardware Manual

15.2

Register Descriptions

15.2.1

Timer Counter (TCNT)

Bit : 7
Initial value : 0
R/W : R/W
TCNT is an 8-bit readable/writable* up-counter.
When the TME bit is set to 1 in TCSR, TCNT starts counting pulses generated from the internal
clock source selected by bits CKS2 to CKS0 in TCSR. When the count overflows (changes from
H'FF to H'00), either the watchdog timer overflow signal (WDTOVF) or an interval timer
interrupt (WOVI) is generated, depending on the mode selected by the WT/IT bit in TCSR.
TCNT is initialized to H'00 by a reset, in hardware standby mode, or when the TME bit is cleared
to 0. It is not initialized in software standby mode.
Note: * TCNT is write-protected by a password to prevent accidental overwriting. For details see
section 15.2.5, Notes on Register Access.
15.2.2

Timer Control/Status Register (TCSR)

TCSR0
Bit : 7
OVF
Initial value : 0
R/W : R/(W)*
Note: * Only a 0 can be written, for flag clearing.
1
TCSR1 *
Bit : 7
OVF
Initial value : 0
R/W : R/(W)*
Notes: *1 In the case of the H8S/2695, only 0 should be written to the TCSR1 register.
*2 Only a 0 can be written, for flag clearing.
6 5
0 0
R/W R/W
6 5
WT/IT TME
0 0
R/W R/W
6 5
WT/IT TME
0 0
2
R/W R/W
4 3
0 0
R/W R/W R/W
4 3
— — CKS2
1 1
— — R/W
4 3
PSS RST/NMI CKS2
0 0
R/W R/W R/W
2 1 0
0 0 0
R/W R/W
2 1 0
CKS1 CKS0
0 0 0
R/W R/W
2 1 0
CKS1 CKS0
0 0 0
R/W R/W
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